Ice creams are consumed and enjoyed by people of almost all age groups. Currently, ice creams are made by two methods. One of the methods is known as continuous method, and another method is known as batch method.
A continuous system typically includes an air injection system that pressurizes the system and begins to introduce air into the mixture, which is then passed through a continuous freezer (heat exchanger). In this dynamic heat exchanger, the mixture contacts the sides of the heat exchanger and is continuously scraped from the sides as it freezes and simultaneously pushed inward and forward, while adding air into the mixture, so that more of the unfrozen solution contacts the frozen sides of the heat exchanger. Overrun is a measure of aeration that is of particular importance in ice cream making as it affects the organoleptic properties, stability, and profitability of ice cream. It is customarily defined by following equation.Overrun=((volume of finished ice cream−volume of mixture used to make the ice cream)/volume of mixture used to make the ice cream)×100%.
The freezer (heat Exchanger) continuously and dynamically freezes the mixture and produces a soft serve ice cream, which is then filled into containers and then sent to a blast freezer to harden. The ice cream, thus produced, is required to be sent to the blast freezer for 45-60 minutes on average to freeze it quickly, harden it, and make it stable to ship and sell. The continuous system thus requires extensive upfront cost, sanitation, and maintenance for successful operation. Hence, continuous ice cream making systems are expensive, large, and usually limited to large scale ice cream manufacturers.
Batch ice cream systems vary in size and can range from small counter top machines to intermediate size store/commercial size machines. In the commercial version of the systems, a liquid ice cream mixture flows from a reservoir into a heat exchanger beater chamber with a beater that incorporates air into the mixture and pushes/spreads the unfrozen portion of the mixture into a thin layer against the frozen walls of the chamber (heat exchanger) while simultaneously scraping away the frozen layer from the surface and pushing it inwards to mix with the rest of the mixture. After a while, the mixture partially freezes and produces a short shelf life soft serve ice cream that must be either consumed immediately or rapidly hardened to increase shelf life and preserve texture.
Home ice cream systems use a very similar system to the batch ice cream system, except that, usually, they have no reservoirs and the freezing/scraping chamber has to be manually loaded. The resulting product is very similar to the commercial batch systems in shelf life and hardness.
Current home and small scale ice cream making systems are slow, cumbersome, and messy. Further, they require sanitation, produce low overrun and low stability products that are difficult to customize. Furthermore, by necessity, these products only produce soft ice cream, as allowing the ice cream to harden would lock up the system and potentially burn out the drive motors.
Both continuous and batch systems require motion during freezing to combat the drop in thermal conductivity that occurs as the outer layers in contact with the freezing system freeze as water ice has lower thermal conductivity than liquid water in solutions of the same composition.
Further, freezing ice cream and other desserts statically in traditional shaped containers results in slow freezing due to the freezing pattern where the outer layers freeze first which reduces their thermal conductivity, concentrates dissolves solids and slows down the freezing of internal portions of the mix as more solids migrate inward, and these central portions become highly concentrated.
New non-traditional ice cream mixtures require pre-whisking before freezing. Whisking the mixture, using traditional methods, would require opening the pods which in an automatic system would cause product to get onto the system. This, in turn, would require cleaning and sanitation after each use. But, having to clean and sanitize the system after every use will reduce the throughput of the system and increase the difficulty of use.
Therefore, there is an unmet need for an improved system and a method for making ice cream which solves above mentioned problems associated with traditional ice cream making systems.